[Bug fortran/71839] New: undefined reference to `_gfortran_caf_stop_str'

[mexas at bristol dot ac.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71839

            Bug ID: 71839
           Summary: undefined reference to `_gfortran_caf_stop_str'
           Product: gcc
           Version: 6.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mexas at bristol dot ac.uk
  Target Milestone: ---

$ caf --version

OpenCoarrays Coarray Fortran Compiler Wrapper (caf version 1.6.0)
Copyright (C) 2015-2016 Sourcery, Inc.

$ mpif90 --version
GNU Fortran (GCC) 6.1.0


caf      -c testAAF.f90 -Wall -I. -I/panfs/panasas01/mech/mexas/mod -g
-fbacktrace -fcheck-array-temporaries 
caf      -o testAAF.x testAAF.o testaux.o -L/panfs/panasas01/mech/mexas/lib
-lcgpack
testAAF.o: In function `MAIN__':
testAAF.f90:(.text+0x846): undefined reference to `_gfortran_caf_stop_str'
testAAF.f90:(.text+0x926): undefined reference to `_gfortran_caf_stop_str'
collect2: error: ld returned 1 exit status
make: *** [testAAF.x] Error 1

cgpack is my coarray library:

$ nm ~/lib/libcgpack.a |grep stop_str
                 U _gfortran_caf_error_stop_str
                 U _gfortran_caf_error_stop_str

It seems ERROR STOP is ok, but STOP is not.